materials: recording equipment, flashcards, a stopwatch, etc.; in many cases computers can do the job: randomising stimuli, displaying stimuli for timed periods, record subjects' reactions to them (e.g. Inquisit: http://www.millisecond.com/)

Possible experimental setups:

two identical groups doing different tasks

two identical groups doing the same task in different conditions

two groups that differ in some specific way (e.g. age, gender, native/non-native speakers)